1. Field of the Invention
This invention relates to a humidity sensor element for detecting a humidity as a variation of electric resistance.
2. Description of the Prior Art
Generally, a certain kind of metal oxide semiconductor has a good water absorbing property and it is known that molecules of water are absorbed into and removed from the metal oxide semiconductor whereby the resistance value of the metal oxide semiconductor varies.
The abovementioned properties can be utilized to make a humidity sensor element. However, conventional humidity sensor elements have disadvantages that the reproductivity is poor, change in lapse of time is great, sensitive speed is slow, and volume resistivity by which detection can be made electrically with high accuracy is not provided.